Ana represented her country in the 2000 Olympic Games in Sydney and won a gold medal in the Pan-American games in Santo Domingo in 2003 . In 2003, she also won the World Track Championship in Paris, France, making her the world champion in the 400 meters. In the 2004 Olympic Games in Athens, the whole of Mexico stopped for one minute to watch Ana run the 400-meter race, where she won the silver medal.